"Barack Obama is going to visit only three states, but that is because he is ahead in the polls.

"He expects that if he visits Florida, North Carolina and Virginia, all states won by the Republicans in the last election, he will solidify the leads he has in those states and that should be enough to put him over the top."

On Sunday, the Illinois senator told a rally of 80,000 people in Ohio, where the Reuters/Zogby poll gave him a six point advantage, that victory appeared to be in reach.

Obama said as he stood in the pouring rain in the city of Cleveland: "Everything looks a little better. Crowds seem to grow and everybody's got a smile on their face.

"You start thinking that maybe we might be able to win an election on November 4."

Al Jazeera's Rob Reynolds, reporting from Ohio, said Obama and Joe Biden, his running-mate, had targeted the state in an attempt to attract voters who had supported Hillary Clinton, Obama's rival, during the long Democratic primary battle.

Another survey taken in the state by the Mason-Dixon polling firm indicated McCain was ahead by two points.

'Mac is back'

In Pennsylvania, McCain told supporters that polls had been wrong before, and would be proved wrong again on election day.

"My friends - the Mac is Back," he said. "I've been in a lot of campaigns, I know when momentum is there. We're going to win Pennsylvania, we're going to win this election."

But the Reuters/Zogby poll put him 11 percentage points behind his rival in Pennsylvania.

The 72-year-old Arizona senator continued his attacks on his opponent's patriotism and tax plans at appearances on Sunday.

McCain leads Obama in two swing states - by five points in Indiana and by one point in North Carolina - according to the poll. Analysts had suggested these traditionally Republican states could fall to the Democratic candidate.

"Obama's lead is very steady. He could be looking at a big day on Tuesday," pollster John Zogby said.

"These are all Republican states except Pennsylvania, and that does not look like it's going to turn for him."

Under the US political system, the president is elected not by direct popular vote but by capturing 270 out of 538 electoral votes distributed throughout the country in a state-by-state contest.

The five states where Obama is ahead, according to the Reuters/Zogby poll, have a combined 76 electoral votes. Taken along with the states won by John Kerry, the defeated Democratic candidate in 2004, Obama would have 328 electoral votes.

However, Obama's leads in Missouri and Florida fall within the margin of error of the polls and many analysts have said that they are too close to call.